| County | Reported* | Tested | Positive | % Tested Positive |
| Alameda | 201 | 5 | 5 | 100% |
| Alpine | - | - | - | - |
| Amador | 2 | - | - | - |
| Butte | 25 | 2 | - | - |
| Calaveras | 5 | - | - | - |
| Colusa | 6 | - | - | - |
| Contra Costa | 218 | 3 | - | - |
| Del Norte | - | - | - | - |
| El Dorado | 35 | 4 | - | - |
| Fresno | 67 | 1 | - | - |
| Glenn | 6 | - | - | - |
| Humboldt | 6 | - | - | - |
| Imperial | 3 | - | - | - |
| Inyo | - | - | - | - |
| Kern | 23 | 1 | - | - |
| Kings | 12 | - | - | - |
| Lake | 8 | 3 | - | - |
| Lassen | - | - | - | - |
| Los Angeles | 310 | 10 | - | - |
| Madera | 6 | - | - | - |
| Marin | 30 | 1 | - | - |
| Mariposa | - | - | - | - |
| Mendocino | 3 | - | - | - |
| Merced | 18 | - | - | - |
| Modoc | - | - | - | - |
| Mono | 1 | - | - | - |
| Monterey | 15 | - | - | - |
| Napa | 16 | - | - | - |
| Nevada | 19 | 1 | - | - |
| Orange | 125 | 14 | - | - |
| Placer | 81 | 13 | - | - |
| Plumas | - | - | - | - |
| Riverside | 73 | 11 | - | - |
| Sacramento | 314 | - | - | - |
| San Benito | 3 | - | - | - |
| San Bernardino | 41 | 3 | - | - |
| San Diego | 173 | 51 | 2 | 4% |
| San Francisco | 33 | - | - | - |
| San Joaquin | 71 | 14 | - | - |
| San Luis Obispo | 28 | 2 | - | - |
| San Mateo | 235 | 72 | - | - |
| Santa Barbara | 25 | 10 | - | - |
| Santa Clara | 299 | 6 | 6 | 100% |
| Santa Cruz | 40 | 7 | - | - |
| Shasta | 8 | 1 | - | - |
| Sierra | 1 | - | - | - |
| Siskiyou | 3 | - | - | - |
| Solano | 63 | 4 | - | - |
| Sonoma | 68 | 3 | - | - |
| Stanislaus | 53 | 1 | - | - |
| Sutter | 6 | 1 | - | - |
| Tehama | 4 | - | - | - |
| Trinity | - | - | - | - |
| Tulare | 19 | 3 | - | - |
| Tuolumne | 4 | - | - | - |
| Ventura | 64 | 1 | - | - |
| Yolo | 108 | - | - | - |
| Yuba | 4 | 2 | - | - |
| State Totals | 2981 | 250 | 13 | 5% |
* Birds in a die-off are not included in reported totals because the deaths are not related to WNV. A die-off is defined as a group of 10 or more same species dead birds unless the species is American Crow.
Source: Vector-Borne Disease Section, California Department of Public Health